May 5 (Reuters) - Payments firm Fiserv ( FISV ) missed

estimates for first-quarter revenue, hurt by weakness in its

merchant and financial solutions units.

Shares of the company slipped 7.7% in premarket trading on

Tuesday. They have lost nearly 66% over the past 12 months.

Traditional fintech firms have come under increasing

pressure as competition intensifies, merchant growth slows and

execution issues drag on growth, with core payments businesses

struggling to keep up momentum.

Wisconsin-based Fiserv ( FISV ) collects fees from merchants, banks

and credit unions for processing payments and transactions.

Processing and services revenue, which makes up more than

four-fifths of Fiserv's ( FISV ) total revenue, edged up 0.6% to $4.07

billion in the quarter.

Revenue in the merchant solutions segment was flat, while

the financial solutions segment posted a 4.8% decline.

Excluding one-time items, the company earned $1.79 per share

during the quarter, beating analysts' estimate of $1.57,

according to data compiled by LSEG.

The results mark the beginning of what Fiserv ( FISV ) has described

as a transition year, following management changes late last

year. In February, the company said it would increase investment

in strategic areas to fix gaps, improve client service and

support stronger second-half momentum.

"Our team is focused on advancing the One Fiserv Action Plan

and while significant work remains, we are encouraged by our

progress," said CEO Mike Lyons.

Adjusted revenue for the quarter stood at $4.68 billion,

compared with analysts' average estimate of $4.73 billion,

according to data compiled by LSEG.

Fiserv's ( FISV ) growth came under pressure in the quarter, with

adjusted operating margin down to 29.7% from 37.8% a year

earlier.