Pace, the set-top box maker, helped lift the FTSE 250, with shares rallying after the US Department of Justice (DoJ) closed its investigation into Arris' acquisition of the company.
Pace's shares rose 7.61 per cent to 435.35p in early afternoon trading.
The DoJ had previously requested information and was investigating the combined businesses position in "optical transmission", which had led to the delay. The transaction is still subject to the approval by competition authorities in Brazil.
"Arris has received approval from regulators in Colombia, Germany, Portugal and South Africa," analysts at Liberum wrote in a note.
"Only Brazil has yet to approve the merger. Given other regulators have approved the deal it would seem likely that Brazil may too."
Liberum maintained its "buy" rating on Pace's stock.
Pace announced its plans to merge with US rival Arris in April. Shareholders in both companies have already approved the deal.