Shares in Computershare have soared by more than 15 per cent as its largest-ever acquisition finally obtained United States anti-trust clearance.

Notice of the clearance, provided on Monday, allows the closure of Computershare's acquisition of the shareowner services business of The Bank of New York Mellon Corporation.

The acquisition was announced in April this year, and was described by Computershare chief executive Stuart Crosby at the time as "the largest acquisition in Computershare's history".

The deal will see Computershare, the world's largest provider of share registry services, significantly increase its market share in the US.

BNY Mellon is the largest provider of transfer agent services in the US, ahead of Computershare.

Transfer agents keep records of the individuals and institutions that hold investments in publicly listed companies and mutual funds.

Computershare stocks hit a three-month high as a result of the clearance.

Computershare shares were up $1.22, or 16.71 per cent, to $8.52 shortly before the close of trade.