diff --git a/packages/rum-core/src/common/compress.js b/packages/rum-core/src/common/compress.js
index 856ccc726..7077e49a4 100644
--- a/packages/rum-core/src/common/compress.js
+++ b/packages/rum-core/src/common/compress.js
@@ -120,26 +120,56 @@ function compressMarks(marks) {
   if (!marks) {
     return null
   }
-  const { navigationTiming, agent } = marks
-  const compressed = { nt: {} }
 
+  const compressedNtMarks = compressNavigationTimingMarks(
+    marks.navigationTiming
+  )
+  const compressed = {
+    nt: compressedNtMarks,
+    a: compressAgentMarks(compressedNtMarks, marks.agent)
+  }
+
+  return compressed
+}
+
+function compressNavigationTimingMarks(ntMarks) {
+  if (!ntMarks) {
+    return null
+  }
+
+  const compressed = {}
   COMPRESSED_NAV_TIMING_MARKS.forEach((mark, index) => {
     const mapping = NAVIGATION_TIMING_MARKS[index]
-    compressed.nt[mark] = navigationTiming[mapping]
+    compressed[mark] = ntMarks[mapping]
   })
 
-  compressed.a = {
-    fb: compressed.nt.rs,
-    di: compressed.nt.di,
-    dc: compressed.nt.dc
+  return compressed
+}
+
+function compressAgentMarks(compressedNtMarks, agentMarks) {
+  let compressed = {}
+
+  if (compressedNtMarks) {
+    compressed = {
+      fb: compressedNtMarks.rs,
+      di: compressedNtMarks.di,
+      dc: compressedNtMarks.dc
+    }
   }
-  const fp = agent.firstContentfulPaint
-  const lp = agent.largestContentfulPaint
-  if (fp) {
-    compressed.a.fp = fp
+
+  if (agentMarks) {
+    const fp = agentMarks.firstContentfulPaint
+    const lp = agentMarks.largestContentfulPaint
+    if (fp) {
+      compressed.fp = fp
+    }
+    if (lp) {
+      compressed.lp = lp
+    }
   }
-  if (lp) {
-    compressed.a.lp = lp
+
+  if (Object.keys(compressed).length === 0) {
+    return null
   }
 
   return compressed
diff --git a/packages/rum-core/test/common/compress.spec.js b/packages/rum-core/test/common/compress.spec.js
index 24888947d..8c8ca8331 100644
--- a/packages/rum-core/test/common/compress.spec.js
+++ b/packages/rum-core/test/common/compress.spec.js
@@ -262,6 +262,116 @@ describe('Compress', function () {
     testMappedObject(transaction, compressed)
   })
 
+  it('should include provided navigation timing marks when compressing transaction model', () => {
+    const expectedNtMarks = {
+      [V3_MAPPING.fetchStart]: 1,
+      [V3_MAPPING.domainLookupStart]: 2,
+      [V3_MAPPING.domainLookupEnd]: 3,
+      [V3_MAPPING.connectStart]: 4,
+      [V3_MAPPING.connectEnd]: 5,
+      [V3_MAPPING.requestStart]: 6,
+      [V3_MAPPING.responseStart]: 7,
+      [V3_MAPPING.responseEnd]: 8,
+      [V3_MAPPING.domLoading]: 9,
+      [V3_MAPPING.domInteractive]: 10,
+      [V3_MAPPING.domContentLoadedEventStart]: 11,
+      [V3_MAPPING.domContentLoadedEventEnd]: 12,
+      [V3_MAPPING.domComplete]: 13,
+      [V3_MAPPING.loadEventStart]: 14,
+      [V3_MAPPING.loadEventEnd]: 15
+    }
+
+    const transaction = generateTransaction(1, true).map(tr => {
+      tr.addMarks({
+        navigationTiming: {
+          fetchStart: 1,
+          domainLookupStart: 2,
+          domainLookupEnd: 3,
+          connectStart: 4,
+          connectEnd: 5,
+          requestStart: 6,
+          responseStart: 7,
+          responseEnd: 8,
+          domLoading: 9,
+          domInteractive: 10,
+          domContentLoadedEventStart: 11,
+          domContentLoadedEventEnd: 12,
+          domComplete: 13,
+          loadEventStart: 14,
+          loadEventEnd: 15
+        }
+      })
+      addTransactionContext(tr, { custom: { foo: 'bar' } })
+      const model = performanceMonitoring.createTransactionDataModel(tr)
+      return model
+    })[0]
+
+    const compressed = compressTransaction(transaction)
+    const compressedNtMarks =
+      compressed[V3_MAPPING.marks][V3_MAPPING.navigationTiming]
+
+    expect(compressedNtMarks).toEqual(expectedNtMarks)
+  })
+
+  it('should handle the absence of timing marks when compressing transaction model', () => {
+    const transaction = generateTransaction(1, true).map(tr => {
+      tr.addMarks({ navigationTiming: null })
+      addTransactionContext(tr, { custom: { foo: 'bar' } })
+      const model = performanceMonitoring.createTransactionDataModel(tr)
+      return model
+    })[0]
+
+    const { marks, navigationTiming } = V3_MAPPING
+    const compressed = compressTransaction(transaction)
+
+    expect(compressed[marks][navigationTiming]).toBe(null)
+  })
+
+  it('should include provided agent timing marks when compressing transaction model', () => {
+    const expectedAgentMarks = {
+      [V3_MAPPING.timeToFirstByte]: 1,
+      [V3_MAPPING.domInteractive]: 2,
+      [V3_MAPPING.domComplete]: 3,
+      [V3_MAPPING.firstContentfulPaint]: 4,
+      [V3_MAPPING.largestContentfulPaint]: 5
+    }
+    const transaction = generateTransaction(1, true).map(tr => {
+      tr.addMarks({
+        navigationTiming: {
+          responseStart: 1,
+          domInteractive: 2,
+          domComplete: 3
+        },
+        agent: {
+          firstContentfulPaint: 4,
+          largestContentfulPaint: 5
+        }
+      })
+
+      addTransactionContext(tr, { custom: { foo: 'bar' } })
+      const model = performanceMonitoring.createTransactionDataModel(tr)
+      return model
+    })[0]
+
+    const compressed = compressTransaction(transaction)
+    const compressedNtMarks = compressed[V3_MAPPING.marks][V3_MAPPING.agent]
+
+    expect(compressedNtMarks).toEqual(expectedAgentMarks)
+  })
+
+  it('should handle the absence of agent marks when compressing transaction model', () => {
+    const transaction = generateTransaction(1, true).map(tr => {
+      tr.addMarks({ agent: null })
+      addTransactionContext(tr, { custom: { foo: 'bar' } })
+      const model = performanceMonitoring.createTransactionDataModel(tr)
+      return model
+    })[0]
+    const { marks, agent } = V3_MAPPING
+    const compressed = compressTransaction(transaction)
+
+    expect(compressed[marks][agent]).toBe(null)
+  })
+
   it('should compress error model', () => {
     const error = generateErrors(1).map((err, i) => {
       let model = errorLogging.createErrorDataModel(err)