A B737 flight crew and a cessna 172 pilot reported a near collision and late instructions from ATC.

Attributes
ACN	1473240
Time
Date	201708
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 350
Person 2
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 35 Flight Crew Total 3000 Flight Crew Type 100
Events
Anomaly	ATC Issue All Types Conflict NMAC
Miss Distance	Horizontal 500 Vertical 300

Narrative:

On approach was given 210 knots and 3000 ft until zzzzz; clear approach. Then we were told to hold 170 knots until ZZZZZ1. We started to descend to 2400 ft past zzzzz. Then ATC ask our altitude and told us to go 2800 ft in the same sentence for traffic. Then we were given 2500 ft for traffic; and told traffic alert; which we did and then got a TA; visually acquired the traffic and executed 'see and avoid' to ensure there was no conflict. ATC asked if we had the airport and then clear for the visual. It was a lot of instructions in a less than a minute. We continued on to the airport and still maintained sa (situational awareness). We were on profile and landed with no other issues.

Original NASA ASRS Text

Title: A B737 flight crew and a Cessna 172 pilot reported a near collision and late instructions from ATC.

Narrative: On approach was given 210 knots and 3000 ft until ZZZZZ; clear approach. Then we were told to hold 170 knots until ZZZZZ1. We started to descend to 2400 ft past ZZZZZ. Then ATC ask our altitude and told us to go 2800 ft in the same sentence for traffic. Then we were given 2500 ft for traffic; and told traffic alert; which we did and then got a TA; visually acquired the traffic and executed 'see and avoid' to ensure there was no conflict. ATC asked if we had the airport and then clear for the visual. It was a lot of instructions in a less than a minute. We continued on to the airport and still maintained SA (Situational Awareness). We were on profile and landed with no other issues.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.