MCI posted a shock profit warning last week, prompting speculation that BT may demand senior resignations and a 10% reduction in the price of the merger.
Analysts said BT could demand $2 billion (#1.18 billion) is cut from the $20 billion cost of merging with the US telco, plus the resignations of two leading MCI executives, finance director Doug Maine and Tim Price, head of the company's telecoms business.
Chiefs at MCI warned the company could lose $800 million in its local telecomms business because of difficulties developing its domestic market.
Regional competitors have been reluctant to let MCI play in the market, while regulators have been slow to open up the sector.
MCI warned that losses could also eat into profits next year. BT said it will review "all aspects of the deal", but it was too early to say whether it would renegotiate the merger.
The deal is just months away from being rubber stamped by the US Federal Communications Commission and analysts believe this will be brought forward to ensure MCI remains competitive in the US.
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